The D Class is the most numerous of the inshore fleet (ILB) and was first introduced in 1963 as the first inflatable lifeboat. The design of the D class has continued to evolve since its introduction. It has been the workhorse of the service for 47 years and was updated in 2003. Fast, light and with a very shallow draught, it can respond rapidly and work in very shallow waters. It is small and highly manoeuvrable, making it an ideal lifeboat for rescues close to shore in fair to moderate conditions and in daylight and darkness. It has a single Mariner 50 hp outboard engine and can be launched by trolley or manually.The D class can be righted manually by its crew who are fully trained in manual capsize procedures.All inshore lifeboats are fitted with inversion-proofed engines that can be restarted following a capsize.